. >> reporter: former congresswoman gabrielle giffords arrived as an unscheduled witness to the first senate hearing on gun violence since the mass shooting at a connecticut elementary school. >> the time is now. you must act. >> reporter: she was nearly killed in a tucson shooting in 2011 and came to capitol hill with her husband, retired astronaut mark kelly, to push for tighter gun restrictions. members of the senate judiciary committee are discussing an assault weapons ban and strengthening background checks. >> i go through background checks. i expect everyone else, too. >> reporter: the nra executive violent wayne lapierre is representing gun owners at the hearing. >> background checks will never be universal because criminals will never submit to them. >> reporter: while gun control is getting new attention here on capitol hill, getting laws passed is an uphill battle. republicans and democrats are strong gun rights supporters. >> the 1994 assault weapons ban did not stop columbine. the justice department found the ban ineffective. >> reporter: dianne feinstein introduced an as